Center-punch.



Patented May 3, 1910.

. Q ill: 1

UNITED STATES PATENT OFFICE.

RICHARD A. HOGGE, OF LOUISIANA, MISSOURI, ASSIGNOR TO FREDRIGK M. MOGRAGKEN, OF LOUISIANA, MISSOURI.

CENTER-P UNCH.

Specification of Letters Patent.

Patented May 3, 1910.

Application filed October 4, 1909. Serial No. 520,863.

To all whom it may concern:

Be it known that I, RICHARD A. Hoecn, a citizen of the United States, residing at Louisiana, Missouri, have invented a certain new and useful Improvement in Center- Punches, of which the following is a full, clear, and exact description, such as will enable others skilled in the art to which it appertains to make and use the same.

This invention relates to center punches such as are used in machine shops for marking a metal plate at the point where a hole is to be drilled therein.

The method usually practiced in cutting an opening in the center or inner ortion of a plate or block of metal is to 'rst scribe the shape of the opening on the plate with a sharp-pointed instrument and then bore a row of holes inside of the scribe mark so as to detach that portion of the plate whichlies inside of the scribe mark. The plate has to be marked or punched at the various points where the holes are to be drilled, and in order that the drill holes will be spaced equal distances apart and also an equal distance inwardly from the scribe mark, the

workman has to first use a pair of dividers to mark the plate at the points where the drill-eentering marks are to be formed, and then form said centering marks with a center punch. This method of laying out work requires a great deal of care and skill on the part of the workman and is costly as the workman consumes a great deal of time in first marking the plate with a pair of,.di-.

viders and then marking or punching it with the center punch.

One object of my invention is to provide a center punch whiehis so constructed that a workman will not have to first mark oif the plate with a pair of dividers or other spacing tool prior to the operation of forming the drill-centering marks in the plate.

Another object is to provide a center punch having means for locating the marking tool or punch at the required distance from the scribe mark on the plate, and also at the required distance from the last punch mark that has been formed in the plate.

Another object is to provide a tool of the character above described which can beadjusted so as to enable it to be used for forming centering marks for drills of different diamete s.

.. Another object is a to provide a center.

punch which comprises a marking tool and a pair of positioning devices which cooperate with each other to arrange the marking tool directly over the point where it is desired to mark the plate, one of said devices being placed on the scribe mark which the workman first forms on the plate, and the other positioning device being placed on the last punch mark formed on the plate.

Still another object of my invention is to provide a tool of the construction referred to in the preceding paragraph having means for adjusting bot-h positioning devices simultaneously and causing one device to move twice as far as the other device so that the holes which are subsequently formed in the plate will just clear each other and also clear the scribe mark.

Other objects and desirable features of my invention will be hereinafter pointed out.

.- Figure l of the drawings is an elevational view of a center punch constructed in ac cordance with my invention; Fig. 2is a top plan view of said tool; Fig. 3 is a horizontal sectional view taken on the line 33 of Fig. 1, looking in the direction indicated by the arrow; Fig. 4: is a horizontal sectional view taken on the line 44: of Fig. 1, looking downwardly in the direction indicated by the arrow; Fig. 5 is a vertical sectional view taken on the line 55 of Fig. 2, looking in the direction of the arrow; Fig. 6 is a perspective view of the sleeve that carries the positioning devices, said sleeve being arranged in an inverted position; Fig. 7 is a perspective view of the adjusting plate arranged in an inverted position; Fig. 8 is a perspective view of oneof the positioning devices; Fig. 9 is a vertical sectional view illustrating one means for locking the adjusting plate; Fig. 10 is a horizontal sectional view taken on approximately the line 1010 of Fig. 1 so as to show the relative positions of the marking tool and the positionin devices; Fig. 11 is a top plan view of a p ate or block of metal and illustrates the way in which my improved center punch is used; and Figs. 12 and 13 are elevational views of slightly modified forms of my in vention.

Referring to the drawings which illustrate the preferred form of my invention, A designaltes the shank of the tool which the workman grasps in his hand, and l designates a punch or marking tool thatis detachably connected to the lower end of said shank, as shown clearly in Fig. 5. A sleeve 2 is loosely mounted on said shank to form a support for a pair of positioning devices hereinafter described, and a ring 3 is arranged in the lower end of said sleeve and permanently connected thereto so as to-form an abutment or stop for the lower end of a coiled expansion spring 4 mounted on the shank A and engaging a shoulder 5 on the said shank. The spring-e tends to force the sleeve 2 and the parts carried thereby downwardly so as to normally hold the marking tool 1 out of contact with the plate or piece of metal being operated on, said shank being provided with a stop 6 that projects into an elongated slot or recess 7 in the sleeve 2 so as to limit the downward movement of said sleeve.

Apair of positioning devices which preferably consist of sharp-pointed members 8 and 9 are pivotally connected intermediate their ends to bifurcated ears or lugs 10 on the sleeve 2, said positioning devices being so arranged that, the point or lower end of the device 9 is twice as far from the end of the markingtool 1 as is the point or lower end of the device 8, this feature being illustrated' clearly in Fig. 10; The upper ends of the devices 8 and- 9'pass through radially disposedslots 11 formed in a flange 12 on the upper end of the sleeve 2, and means is provided for rocking said devices on their pivots so as to move them relatively to the marking tool 1 and thus permit the tool to be used with different-sized drills.

In the construction herein shownthe means for adjusting the positioning devices consists of a plate 13 arranged above thefiange 1 2 on the sleeve- 2 in such amannerthat it can be turned or rotated: about the shank A as an axis. vi'ded with cam-shaped slots 8 'and 9* intowhich the upper ends of the positioning devices 8 and 9 project so that said-deviceswill be rocked on their f'ulcrums whenever the plate 1 3 is" turned. Said plate is-'pro videdon its under side with lt-shaped pro jectionslt that project underneath the-flange 1 2 011: the upper end of the sleeve 2* so as to prevent the plate from moving relatively to said sleeve, and some suitable means is provided for lbcking the plate its ad justed position. The means illustrated" in Fig. 1 for locking said plateconsists of a clamping nut 15 mounted on a screw threaded stu' d l ft which projects upwardly from the flange 12 through an arc-shaped slot 17 in I the plate 13 the nut 1 5 being, adapted to be screwed downwardly so as to clamp the plate 13 tightly against the flange-12. The means illustrated in 'Fig. 9 for the flange 1 2 and provided with a head 18* that beams upon the plate 13 when; fliesleeve The plate 13' is pro 7 ocking the plate 13 consists of a sleeve=18= screwed into:

18 is screwed downwardly, the shank A of the tool passing; through the sleeve l8, as shown clearly in Fig. 9. The peripheral edge of the plate 13 is preferably knurled so as to enable it to be manipulated easily, and the peripheral edge of the flange 12 is provided with a scale or graduation marks 19, as shown in Fig. 1, with which one of the L-shaped devices 1 1 on the under side of the plate cooperates so as to assist the workman in adjusting'the tool.

In laying out a plate inwhich an opening is tobe formed" the workman first scribes the plate at -with a sharp=pointed tool so as to outline the opening, and if a quarter-inchdrill is to be used to drill a row of holes in the plate to detach the center portion of the plate, the workman picks up the center punch and manipulates the plate 12 thereof until the scale 19 shows that the positioning device 8 is an eighth of an inch away from the end of the marking tool 1-, and the positioning device 9 1s one fourt'h of an inchaway from the end of said marking tool. He then places the positioning device 8 on the scribe mark 20: and strikes the shank A a blow so as to force the marking tool 1 into the plate to make a centering mark for the drill; The positioning device 9 isthen insertecl in the punchmark that has: just been formed in the plate and: the positioning device 8 is placed on the scribe 20 and the shank A is struck another blow so as to form a seconddri llcentering mark. These operations are repeated until the entire dis-- ta-nce around the scribe mark has been traverse'd Practically no" skill on the part of the workman is: required to lay out theplate after it has-been scribed for he simply has to arrange the positioning device 8 on the scribe mark and the positloning device 9 in the last punch mark that the tool I has formed in the plate, said two devices cooperating with each other to locate the marki-ng tool an eighth of an inch inwardly from the scribe mark 20 and a quarter of an: inch in advance of the last punchmark that-has been formeda- If a one-eighth inch drill is to be used the workman manipulatesthe plate 1% until the positioning device 8 is spaced a sixteenth of an inch from, the marking tool 1 and the positioning device 9* an eighth of an inch fromsaid' markingtool the rotary movement of the pil'ate 1 3= causing the positioning device 9= to move twice asfar' as the positioning device 8 toward and away from the marking tool.

A center punchof this construction oven comes the necessity o-fi first marking" offi the plate with a pair on dividers; it enables a vwcrkman to lay out a plate quickly and without exercising a great deal of it enables: a workman to lay out, a piece of it reduces the liability of an error being made in laying out a plate in which an irregular-shaped opening is to be formed.

While I have herein shown my invention applied to an ordinary center punch that is adapted to be struck a blow with a hammer I do not wish it to be understood that my broad idea is limited to this exact construction for the same idea could be embodied in an automatic center punch such, for example, as those in which a blow is imparted to the marking tool by means of a spring-actuated device arranged in the hollow handle or shank of the punch.

It is, of course, preferable to provide the tool with means for adjusting the positioning devices 8 and 9 but, if desired, said positioning devices could be rigidly connected to the movable sleeve, such a structure being illustrated in Fig. 13 wherein the reference character 90 designates one of the positioning devices which is rigidly connected to a sleeve 20 loosely mounted on the shank of the tool.

In F ig. 12 I have illustrated a tool in which both positioning devices are positively connected at their upper ends to the flange 12 at the upper end of the sleeve 2 a plate 13 being rotatably mounted on said sleeve for adjusting said positioning device relatii 'ely to the marking tool.

Having thus described my invention, what I claim as new and desire to secure by Letters Patent is:

1. A center punch provided with positioning devices which consist of pivotally mounted members that are adapted to rest stationary on the work when the impression tool is actuated, and means for adjusting the points or lower ends of said members relatively to the impression tool of the punch.

2. A center punch provided with movable positioning devices that are adapted to rest upon the work and thus arrange the impression device in proper position, an actuating member for adjusting said devices, and means for locking said actuating member.

3. A center punch provided with a plurality of pivotally mounted positioning de vices, a rotatable member having camshaped surfaces which impart movement to said devices, and means for locking said member.

4. A center punch having a sleeve mounted on the shank of the punch, positioning devices pivotally connected to said sleeve, and means carried by said sleeve for adjusting said devices.

5. A center pii'nch having a sleeve mounted on the shank of the punch, positioning devices pivotally connected to said sleeve, and a rotatable member carried by said sleeve and provided with cam-shaped surfaces that cooperate with said devices to impart movement thereto.

6. A center punch provided with a sleeve that is mounted on the shank of the punch, pivotally mounted positioning devices car ried by said sleeve, a rotatable member carried by said sleeve and provided with camshaped slots into which the upper ends of said positioning devices project, and means for locking said rotatable member to said sleeve.

7. A center punch comprising positioning devices that are adapted to rest upon the material being operated on, and a movable marking tool normally spaced away from said material and adapted to be forced into engagement with same when said positioning devices remain at rest.

8. A center punch comprising positioning devices that are adapted to be held at rest upon the material being operated on, a marking tool, and yielding means for normally sustaining the point of said tool above the surface of the material being operated on.

9. A center punch provided with a shank, a sleeve loosely mounted on said shank, a spring interposed between a shoulder on said sleeve and a shoulder on said shank for holding the sleeve in a certain position, and positioning devices carried by said sleeve and adapted to be held at rest on the work when the punch is actuated.

10. A center punch provided with ashank, a sleeve loosely mounted on said shank, a spring interposed between a shoulder on said sleeve and a shoulder on said shank for holding the sleeve in a certain position, positioning devices carried by said sleeve, and cooperating means on said shank and sleeve for limiting the movement of one part relatively to the other.

11. A center punch comprising a shank provided with a marking tool, a sleeve loosely mounted on said shank and provided at its upper end with a flange, a coiled expansion spring interposed between a shoulder on said shank and a shoulder on said sleeve, pivotally mounted positioning devices carried by said sleeve, a rotatable member arranged above said flange and provided with means for actuating said positioning devices, and means for preventing said member from moving vertically relatively to said flange.

In testimony whereof I hereunto iLfllX my signature in the presence of two witnesses, this 29th day of September 1909.

RICHARD A. HOGGE.

Witnesses:

WILLIAM CUREEN, J. P. CHANDLER.

It is hereby certified that Letters Patent No. 956,765, granted May 3, 1910, upon the application of Richard A. Hogge, of Louisiana, Missouri, for an improvement in Center-Punches, were erroneously issued to Fredrick M. McOracken, as

assignee of the entire interest in said invention, whereas said Letters Patent should have been issued to the inventor, said Hngge and Fredrick M lfi'Omckemjoz'ntly,

said McCracken being owner of one'lialf interest only; and that the said Letters Patent should be read with this correction therein that the same may conform to the record of the case in the Patent Office.

Signed and sealed this 24th day of May, A. D.., 1910.

C. O. BILLINGS,

Acting Commissioner of Patents.

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